Stanford Research SR620 Universal Time Interval/Frequency Counter 1.3 GHz 25 ps

The Stanford Research SR620 is a universal time interval and frequency counter engineered for precision measurement of timing and spectral parameters up to 1.3 GHz. It delivers 25 ps RMS single-shot time interval resolution and frequency measurement to 11 digits within 1 second, supporting measurements from 0.001 Hz to 1.3 GHz. The instrument simultaneously measures pulse width, rise/fall time, period, and phase (0.001° resolution), while performing event counting across configurable sample sizes from 1 to 1 million.

– Technical Specifications

• Time Interval Measurement: 25 ps RMS single-shot resolution; ±1000 second range with 50 ps relative accuracy and 500 ps absolute accuracy
• Frequency Range: 0.001 Hz to 1.3 GHz; 11-digit resolution in 1-second measurement
• Phase Measurement: 0.001° resolution
• Input Impedance: Selectable 1 MΩ or 50 Ω
• Input Coupling: AC or DC
• Maximum Input Voltage: ±5 Vp
• Input Sensitivity: 60 mV RMS from 1 to 40 MHz
• DC Voltage Measurement: 0.3% accuracy on ±20 VDC range
• Timebase: 10.000 MHz standard (1×10⁻⁶/year aging); optional ovenized timebase with 5×10⁻¹⁰/day aging; external 5 MHz or 10 MHz input supported
• Statistical Analysis: Mean, standard deviation, Allan variance, minimum, and maximum automatically calculated
• Power Input: 100/120/220/240 VAC (±5%, −10%), 50/60 Hz; 70 W consumption

– Key Features

• Multi-parameter measurement: time interval, frequency, pulse width, rise/fall time, period, phase, and event counting
• Configurable sample acquisition from single-shot to 1 million measurements
• Dual analog scope outputs (±5 V horizontal, ±4 V vertical) with histogram and strip-chart display modes

– Typical Applications

Precision timing characterization, frequency stability analysis, jitter measurement, signal integrity validation, and phase coherence testing in laboratory and production environments.

– Compatibility & Integration

• GPIB (IEEE-488.2): ~150 ASCII or 1400 binary responses per second
• RS-232: Baud rates 300 to 19.2 kbaud
• Analog Output: XY scope connectivity for waveform display on external oscilloscopes